sidebar: what each tab's panes are saying, said under the tab (tab_bar_status)

Panes already announce a one-line status over OSC 5577, and it rendered
in exactly two places -- both inside the pane's own frame, which is the
one place you are not looking when you most want it. The sidebar has
the vertical room the top strip never had: under each tab, up to
tab_bar_status rows of what the panes inside said, in tree order, dim
like the pane count. A dead pane's row says how it died instead
(exit_words), the same substitution its own frame makes.

The cap's last row is spent on an ellipsis rather than one more status
pretending the list is complete, and a status cut to the sidebar's
width ends in one too -- 'building 3' is a different fact than
'building 3/7'. Each row is a find: hit, the verb that already means
'go to this pane', so clicking a status jumps to the pane that said it,
across tabs. Freshness costs nothing new: an OSC status marks the pane
dirty, the same path the bell indicator rides out of background tabs.

1 files changed, 89 insertions, 0 deletions

diff --git a/tests/test_tab_bar.py b/tests/test_tab_bar.py
index 842d421..9342905 100644
--- a/tests/test_tab_bar.py
+++ b/tests/test_tab_bar.py
@@ -119,6 +119,91 @@ def test_pad_pushes_the_list_down():
         )
 
 
+def _status(s, text):
+    s.send(rf"\e]5577;1;status;{text}\e\\")
+    s.settle(30)
+
+
+def test_status_rows_sit_under_their_tab():
+    with Session(SH, cols=90, rows=20, config=LEFT) as s:
+        s.settle(30)
+        pane = s.pane(0)["id"]
+        _status(s, "building 3/7")
+        s.api("new-tab")
+        s.settle(30)
+        snap = s.snapshot()
+        check(
+            "a pane's OSC status is a row under its tab",
+            "building 3/7" in snap.line(3)[:W],
+            repr(snap.line(3)[:W]),
+        )
+        check(
+            "the other tab moved down to make room",
+            snap.hit_at(1, 4) == "tab:2",
+            str(snap.hit_at(1, 4)),
+        )
+        check(
+            "the row is a door to the pane that said it",
+            snap.hit_at(2, 3) == f"find:{pane}",
+            str(snap.hit_at(2, 3)),
+        )
+        # We are in tab 2: clicking the status row is a cross-tab jump.
+        s.click(2, 3)
+        s.until(lambda _: s.tabs()[0]["active"])
+        check("clicking it selects that tab", s.tabs()[0]["active"], str(s.tabs()))
+        check(
+            "...and focuses that pane",
+            s.focused()["id"] == pane,
+            str(s.focused()["id"]),
+        )
+
+
+def test_status_cap_spends_its_last_row_on_the_ellipsis():
+    capped = _cfg(f'tab_bar_side "left"\ntab_bar_width {W}\ntab_bar_status 1\n')
+    with Session(SH, cols=90, rows=20, config=capped) as s:
+        s.settle(30)
+        _status(s, "first")
+        s.api("split", dir="cols")
+        s.settle(30)
+        _status(s, "second")
+        snap = s.snapshot()
+        check(
+            "over the cap, the row says there was more",
+            snap.line(3)[:W].strip() == "\u2026",
+            repr(snap.line(3)[:W]),
+        )
+        check(
+            "an ellipsis is not a door",
+            snap.hit_at(2, 3) is None,
+            str(snap.hit_at(2, 3)),
+        )
+        check(
+            "and only the cap's rows were spent",
+            snap.hit_at(1, 4) == "newtab",
+            str(snap.hit_at(1, 4)),
+        )
+
+
+def test_a_long_status_is_cut_and_says_so():
+    with Session(SH, cols=90, rows=20, config=LEFT) as s:
+        s.settle(30)
+        _status(s, "a status far too long for the sidebar")
+        row = s.snapshot().line(3)[:W]
+        check(
+            "the status stops at the sidebar's edge", row.endswith("\u2026"), repr(row)
+        )
+
+
+def test_a_dead_pane_reports_its_exit_instead():
+    # Wider than the default: "exited: status 3" plus the indent is 19 cells,
+    # and the point here is the words, not the (already tested) truncation.
+    kept = _cfg('tab_bar_side "left"\ntab_bar_width 24\nkeep_dead "all"\n')
+    with Session(["/bin/sh", "-c", "exit 3"], cols=90, rows=20, config=kept) as s:
+        s.until(lambda snap: "exited" in snap.line(3))
+        row = s.snapshot().line(3)[:24]
+        check("how it died replaces what it last said", "status 3" in row, repr(row))
+
+
 def test_narrow_terminal_falls_back_to_top():
     # 40 < width + min_pane cols + 4: the sidebar would leave no room for the
     # pane it is chrome for, so the strip goes back to the top row.
@@ -153,6 +238,10 @@ if __name__ == "__main__":
     test_sidebar_rows_click_like_the_strip()
     test_right_sidebar_takes_the_other_edge()
     test_pad_pushes_the_list_down()
+    test_status_rows_sit_under_their_tab()
+    test_status_cap_spends_its_last_row_on_the_ellipsis()
+    test_a_long_status_is_cut_and_says_so()
+    test_a_dead_pane_reports_its_exit_instead()
     test_narrow_terminal_falls_back_to_top()
     test_growing_back_restores_the_sidebar()
     sys.exit(report())